Water-permeability stretch knitted fabric

ABSTRACT

The water-permeability stretch knitted fabric has a multi-layered structure including at least two layers, namely the outer layer and the inner layer, wherein 30% or more of the outer layer of the knitted fabric is accounted for by composite fiber multifilament yarns composed of two types of polyester polymer materials adhered to each other side by side in the fiber&#39;s length direction, the water-permeability of the knitted fabric being such that both the water absorption back-and-front moisture content ratio and the water absorption back-and-front diffusion area ratio between the outer layer and the inner layer are two or more, and the average for the stretch percentages and that for the stretch recovery percentages in the longitudinal and transverse directions of the knitted fabric being 55% or more and 60% or more, respectively.

RELATED APPLICATIONS

This is a §371 of International Application No. PCT/JP2006/315701, withan international filing date of Aug. 9, 2006 (WO 2008/018122 A1,published Feb. 14, 2008).

TECHNICAL FIELD

This disclosure relates to a water-permeability stretch knitted fabricfor clothing and other materials that is high in sweat removingperformance and also high in stretchability and stretch recovery whichare essential properties for comfortable clothing.

BACKGROUND

Knitted fabrics can be higher in stretchability than woven fabrics dueto their fabric structure, enabling easy movement of the wearer.Accordingly, knitted fabrics have been conventionally used in manyfields for general clothing such as innerwear, outerwear, andsportswear; hosiery such as pantyhose; clothing materials such aslining, interfacing; and industrial materials such as chair upholstery.

In recent years, however, there have been greater demands for knittedfabrics, particularly for innerwear, sportswear, and lining, that fitthe body of the wearer comfortably to enable easy movement and show highsweat removing performance during perspiration. To meet them, varioustechnical improvements have been proposed to provide better fibers andknit structures for knitted fabrics.

In particular, many studies have been carried out about a new type ofstretch knitted fabrics called spandex that combine nylon fiber,polyester fiber, or cotton yarns with specific polyurethane-basedelastic fibers to achieve high stretchability and stretch recovery.

Though such polyurethane-based elastic fibers have high stretchability,however, combining them with other fibers will lead to stiff texturebecause of inherent properties of polyurethane, leading to deteriorationin texture and drape property of the knitted fabrics. When combined withpolyester fibers, furthermore, they cannot be dyed easily with dispersedyes designed for polyester, and this will cause persistent problemssuch as pollution of washing wastewater and decrease in the wet rubbingfastness of the knitted fabrics, leading to difficulty in achievingintended colors by dying as well as requiring a complicated dyeingprocess comprising strong reduction cleaning. In addition, a decreasedheat resistance can cause problems such as roughening of the outer ofthe knitted fabrics. Polyurethane-based elastic fibers, furthermore,require very large costs (see JP-B-H01-040137).

Some methods have been adopted, for instance, to develop stretchabilityby combining polyester fibers or nylon fibers that are false-twisted sothat a torque is produced by twisting and untwisting or by combiningpolybutylene terephthalate fibers, although still failing to provideknitted fabrics with a sufficiently satisfactory stretchability (seeJP-A-H06-101116).

It could therefore be helpful to provide water-permeability stretchknitted fabrics that have high stretchability and stretch recovery, aswell as water-permeability.

SUMMARY

We provide water-permeability stretch knitted fabrics that include aknitted fabric of a multi-layered structure, comprising at least twolayers, namely the outer layer and the inner layer, wherein 30% or moreof the outer layer is accounted for by multifilament yarns (a) thatcomprise composite fiber filaments composed of two types of polyesterpolymer materials adhered to each other side by side in the fiber'slength direction, the water-permeability of the knitted fabric beingsuch that both the water absorption back-and-front moisture contentratio and the water absorption back-and-front diffusion area ratiobetween the outer layer and the inner layer are two or more, and theaverage for the stretch percentages and that for the stretch recoverypercentages in the longitudinal and transverse directions of the knittedfabric being 55% or more and 60% or more, respectively.

These fabrics serve to simultaneously maintain water-permeability,stretchability, and stretch recovery, which cannot be achieved in theconventional knitted fabrics. Thus, we provide thin to medium-thickwater-permeability stretch knitted fabrics with sufficiently high sweatremoving performance and stretchability to be produced efficiently andeconomically, serving to provide useful materials for sportswear,innerwear, lining, and other articles used in various fields.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates typical load vs. stretch recovery curves for themulti-layered structure knitted fabric.

FIG. 2 schematically shows a cross section of the side-by-side typecomposite fiber filaments that constitute the multifilament yarns (a).

FIG. 3 illustrates the knitting diagrams used to produce knittingfabrics in Examples 1 to 3 and Comparative Examples 1 and 3.

FIG. 4 illustrates the knitting diagram used to produce knitting fabricsin Comparative Example 2.

EXPLANATION OF SYMBOLS

-   -   L1: elongation of knitted fabric    -   L2: strain elongation of knitted fabric    -   L3: recoverable elongation of knitted fabric    -   (1) to (3): cross section of fiber    -   α: circumscribed circle of cross section of fiber    -   β: inscribed circle of cross section of fiber    -   A: straight line connecting two concave portions    -   B: longest portion of the straight line at right angles to the        line A    -   F1 to F8: numbers of yarn feeding ports of the knitting machine    -   D1 to D5: knitting needle on the dial side    -   C1 to C6: knitting needle on the cylinder side    -   E1: yarn on the inner layer side of the knitted fabric    -   E2: yarn on the outer layer side of the knitted fabric

DETAILED DESCRIPTION

After studying the aforementioned issues in producing water-permeabilitystretch knitted fabrics that have high stretchability, stretch recovery,and water-permeability while maintaining required mechanical strength,chemical resistance, dyeing processability, softness, and fluffiness, wefound that the problem would be solved completely when they produced themulti-layered structure knitted fabric using a specific type ofmultifilament yarns to constitute the outer layer of the multi-layeredstructure knitted fabric.

In general, clothing such as innerwear, sportswear, and lining is wornin contact with the skin and, therefore, they are required to maintainhigh sweat absorption performance continuously for a long period of timeto control heavy perspiration from the skin during exercise and labor insummer and also have high drying ability to allow sweat to transpirerapidly into the air and high washability to resist frequent washing.

It is generally known that high-count multifilaments, modifiedcross-section multifilaments and spun yarns with a low monofilamentfineness tend to contain many small interfiber gaps to cause highwater-permeability due to the capillary mechanism and, therefore, theyare suited to produce water-permeability knitted fabrics. Thus, if suchhigh-count multifilaments, modified cross-section multifilaments or spunyarns with a low monofilament fineness are used to constitute the outerlayer of multi-layered structure knitted fabrics, sweat absorbed throughthe inner layer of the multi-layered structure knitted fabrics will berapidly transported to the outer layer, serving to prevent stickinessand chilly feeling during perspiration and achieve quick-dryingperformance.

These techniques are combined with others to provide clothing such asinnerwear, sportswear, and lining that can maintain high sweatabsorption performance continuously for a long period of time to controlheavy perspiration from the skin during exercise and labor in summer andthat, in addition to this, specific multifilament yarns are used alongwith a specific multi-layered structure to provide water-permeabilitystretch knitted fabrics that have satisfactorily high stretchability.

The water-permeability stretch knitted fabrics contain multifilamentyarns (a) that comprise composite fiber filaments composed of polyesterpolymer materials of different types adhered to each other side by sidein the fiber's length direction and having at least one concave portion.Side-by-side type composite fiber filaments that constitute themultifilament yarns (a) are composed of polymer materials that differ inpolymer species, intrinsic viscosity, copolymerization composition, orcopolymerization degree adhered to each other to develop crimps as aresult of differences in elastic recovery percentage or shrinkagecharacteristics. Thus, we make clever use of these characteristics.Specifically, the side-by-side type composite fiber filaments composedof polymers with different viscoelasticities will suffer a concentratedstress in the high-viscosity component during spinning or stretching,leading to different internal strains between the two components. Thedifference caused in the elastic recovery percentage after thestretching and that caused in the heat shrinkage degree during the heattreatment step of the knitted fabrics leads to shrinkage in thehigh-viscosity component, and as a result, a strain will develop in themonofilaments to produce three-dimensional coil crimps. It can be saidthat the diameter of these three-dimensional coils and the number ofcoils per unit fiber length depend on the difference in the degree ofshrinkage (including the difference in elastic recovery percentage)between the high-shrinkage component and the low-shrinkage component,indicating that the diameter of these three-dimensional coils decreasesand the number of coils per unit fiber length increases with thedifference in the degree of shrinkage.

Coil crimps in stretch material are required to be small in coildiameter, large in the number of coils per unit fiber length (for goodelongation characteristics and good appearance), high in resistance tocoil flattening (small coil flattening relative to stretch recovery, andhigh stretch retention performance), and small in hysteresis loss duringcoil's stretch recovery (highly springy, fitting comfortably). The coildiameter should preferably be 250 μm or less, more preferably 200 μm orless.

With respect to the phase of coils produced in the length direction ofthe multifilament yarns, each multifilament yarn will work like a springwhen all filaments constituting the yarn are in the same coil phase. Aknitted fabric produced from such yarns will be fluffy and soft, andhave a beautiful surface with fine crimps. When the filamentsconstituting the yarn are not in the same coil phase, on the other hand,the filaments in each multifilament yarn will be bulging randomly, andappear to be false-twisted multifilament yarns that could result afterfalse-twisting and untwisting. A knitted fabric produced from theseyarns will be fluffy and soft, and have a beautiful flat surface.Furthermore, the random arrangement of the filaments will serve toproduce many small gaps between single yarns, and this leads to anincrease in the water-permeability of the fiber, hence that of theknitted fabric, resulting in a good water-permeability stretch knittedfabric.

Multifilament yarns (a) in which the side-by-side type composite fiberfilaments are in the same coil phase should be used when the knittedfabric needs to have crimps on its surface, while multifilament yarns(a) in which the side-by-side type composite fiber filaments are not inthe same coil phase should be used when it needs to have a flat surface.

To produce multifilament yarns (a) in which the side-by-side typecomposite fiber filaments are in the same coil phase, the side-by-sidetype composite fiber filaments should be lower in the degree ofmodification. Low-modification filaments can move easily in the fibers,allowing the filaments to come in the same coil phase. For our fabrics,however, it is important to improve the water-permeability, and themultifilaments used need to have at least one concave portion and at thesame time have a modification degree of 1.3 or more. Multifilament yarns(a) of filaments in the same coil phase will be produced easily bywinding the multifilament yarns continuously while maintaining themunder tension during the stretching and winding steps.

To produce multifilament yarns (a) in which the side-by-side typecomposite fiber filaments are not in the same coil phase, on the otherhand, the side-by-side type composite fiber filaments should be higherin the degree of modification. High-modification filaments cannot moveeasily in the fibers, and the shifts in phase, once caused, will notdisappear during the yarn production step, leading to multifilamentyarns in which the filaments are not in the same coil phase. As thedegree of modification increases, however, the fibers will become morelikely to fracture and start to suffer fibrillation, leading todeterioration in processability and quality. Thus, the degree ofmodification must be 6.0 or less. Multifilament yarns (a) of filamentsin the same coil phase will be produced easily by providing a relaxationstep between the stretching and winding steps to relax the multifilamentyarn before winding it continuously.

A water-permeability stretch knitted fabric having a good overallbalance can be produced by maintaining good inherent characteristics ofpolyester, such as moderate bending strength, drape, and high dyefastness, while meeting the aforementioned requirements. Here, thecharacteristics of the high-shrinkage component (high-viscositycomponent) are the key to meeting the requirements for the coilcharacteristics. The stretching properties of the coils depend mainly onthose of the high-shrinkage component working on the low-shrinkagecomponent as fulcrum, and accordingly, the polymer material used as thehigh-shrinkage component should have high stretchability and stretchrecovery.

Thus, we carried out studies to achieve the characteristics whilemeeting the good characteristics of polyester, and found that it waspreferable to use a polyester material composed mainly ofpolytrimethylene terephthalate (hereinafter referred to as PTT) for thehigh-shrinkage component. The PTT fiber has a very high stretch recoveryperformance while having as good dynamic and chemical characteristics asthose of such representative polyester fibers as polyethyleneterephthalate (hereinafter referred to as PET) fiber and polybutyleneterephthalate (hereinafter referred to as PBT) fiber. It is consideredthat this is attributed to the fact that the methylene chain in thealkylene glycol portion of the PTT crystal structure forms agauche-gauche structure (in which the molecule chains are bent at 90degrees) and that the density of the constraint points due to theinteraction (stacking, parallel) among benzene rings is low while theflexibility is high, allowing the methylene groups to rotate smoothly toachieve easy stretching and recovery of the molecular chains.

Here, PTT is a polyester consisting of terephthalic acid as the majoracid component and 1,3-propanediol as the major glycol component. Thematerial to be used, however, may contain 20 mol %, more preferably 10mol % or less, of a copolymerization component that can form an esterbond of another type. The compounds that can be used forcopolymerization include, but not limited to, dicarboxylic acids such asisophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipicacid, dimeric acid, sebacic acid, and 5-sodium sulfoisophthalic acid;and diols such as ethylene glycol, diethylene glycol, butanediol,neopentyl glycol, cyclohexanedimethanol, polyethylene glycol, andpolypropylene glycol. In addition, the material may contain, as needed,titanium dioxide as delustering agent, fine particles of silica andalumina as lubricant, hindered phenol derivative as antioxidant, andother additives such as color pigment.

There are no specific limitations on the polyester material for thelow-shrinkage component if it is a fiber-forming polyester that hasstable yarn-forming capability as well as high interface adhesivenesswith the high-shrinkage component. Fiber-forming PTT, PET, and PBTpolymers are preferred as material for the low-shrinkage component inconsideration of their dynamic characteristics, chemicalcharacteristics, and raw material prices.

The melt viscosity of the PTT material at the spinning temperatureshould preferably be 1.0 to 5.0 times that of the other, i.e.,low-shrinkage, component at the spinning temperature. If the ratio isadjusted to 1.0 or more, preferably 1.1 or more, the PTT material willreceive a larger spinning stress during the fiber formation step in thespinning process, leading to a higher crimp forming capability.Adjusting the ratio to 5.0 or less, preferably 4.0 or less, on the otherhand, will facilitate the control of the composite morphology, and makeit possible to maintain the bending of the polymer discharged from theorifice at a sufficiently low level.

The optimum composition ratio of the two components depends on theiryarn-forming capability and the uniformness of the coil size in thefiber's length direction, and specifically the ratio between thehigh-shrinkage component and the low-shrinkage component shouldpreferably be 75:25 to 35:65 (in terms of weight percentage), morepreferably 65:35 to 45:55.

There are no specific limitations on the cross-sectional shape of theside-by-side type composite fiber filaments that constitute themultifilament yarns (a), but their cross section should preferably haveat least one concave portion with a modification degree in the range of1.3 to 6.0. Such cross-sectional shapes include multilobar, C-shape,M-shape, H-shape, X-shape, W-shape, 1-shape, and +shape. Multifilamentyarns (a) comprising side-by-side type composite fiber filaments with across section of snowman-like shape as shown in FIG. 2 a are preferredin terms of the balance among the crimp-forming performance,water-permeability, and texture.

The snowman-like shape for the cross section of the fiber consists oftwo adjacent circles or ellipses connected to each other as shown inFIG. 2 a, and the two circular portions should preferably comprisepolymers of different compositions. There are no specific limitations onthe snowman-like cross section of the fiber if its modification degreeis in the range of 1.3 to 6.0, but the ratio (B/A) between the length ofthe straight line connecting the two concave points, A, and that of thelongest portion of the straight line at right angles to the former, B,should preferably be in the range of 1.0 to 5.0. The ratio B/A shouldmore preferably be in the range of 2.0 to 4.0 considering theyarn-forming performance and the physical properties of the resultingknitted fabric.

The side-by-side type composite fiber filaments should preferably have amonofilament fineness in the range of 0.1 to 11 decitex. Side-by-sidetype composite fiber filaments with a monofilament fineness of 11decitex or less will serve to produce knitted fabrics with a softtexture that can be used preferably as material for clothing. Moreover,it should more preferably be 5.5 decitex or less for fabrics that willbe used in direct contact with the skin. Good composite yarns can beproduced and high stretchability attributable to the crimp structure canbe achieved if the fineness is 0.1 decitex or more, more preferably 1.1decitex or more. Furthermore, combined filament yarns comprisingmonofilaments different in fineness may also be used. The use ofcombined filament yarns comprising monofilaments different in finenessis preferred because it can serve to produce soft and firm knittedfabrics.

The multifilament yarns (a) should preferably be filaments yarns with atotal fineness of 22 to 330 decitex. Furthermore, the total finenessshould more preferably be in the range of 33 to 110 decitex if the yarnsare to be used for production of thin fabric, or 55 to 220 decitex forthick fabrics.

A knitted fabric of a specific multi-layered structure with highwater-permeability and stretchability is produced by using theaforementioned multifilament yarns (a) so that they account for 30% ormore of the outer layer of the knitted fabric.

Specifically, the water-permeability stretch knitted fabric ischaracterized in that it has high water-permeability such that the ratioof the water absorption back-and-front moisture content of the outerlayer to that of the inner layer of the knitted fabric is two or moreand the water absorption back-and-front diffusion area ratio betweenthem is also two or more. The water absorption back-and-front moisturecontent ratio and water absorption back-and-front diffusion area ratioshould preferably be three or more, more preferably four or more. Thefabric would feel sticky on the sweaty skin if these ratios are lessthan two.

Adjusting these ratios to two or more will allow the knitted fabric tohave a high water-permeability and permeability to facilitate sweatsecreted during exercise or labor to be absorbed through the knittedfabric's inner layer that is in contact with the skin and transportedinto the outer layer and at the same time show high performance indiffusing, transpiring, and drying the sweat in the knitted fabric'souter layer, serving to reduce the stickiness during heavy perspirationand achieving high comfortability.

To achieve a high water-permeability such that both the water absorptionback-and-front moisture content ratio and the water absorptionback-and-front diffusion area ratio are two or more, it is important forthe side-by-side type composite fiber filaments constituting themulti-filament yarns (a) to have such a modified cross-section shape asdescribed above and for the multifilament yarns (a) to account for 30 wt% or more of the outer layer of the multi-layered structure knittedfabric. In general, conventional water-permeability stretch knittedfabrics have been produced by using yarns having a modified crosssection with portions concave in the fiber's length direction or yarnswith a low filament fineness to improve the water-permeability whileusing spandex or highly crimped yarns to improve the stretchability. Asdescribed above, however, the use of spandex would cause problems suchas stiffening of texture, decrease in fast-ness, need of more cumbersomeprocessing, and increase in cost, while satisfactory stretchabilitycannot be achieved with highly crimped yarns. With this disclosure, ahigh water-permeability and stretchability are achieved simultaneouslyby using the multifilament yarns (a) comprising side-by-side typecomposite fiber filaments with a specific modified cross section,enabling knitted fabrics to be produced more easily and efficiently. Ifthe multifilament yarns (a) account for 30 wt % or more of the outerlayer, it will be possible for the sweat absorbed through the innerlayer of the multi-layered structure knitted fabric to be transportedrapidly into the outer layer, serving to prevent stickiness and chillfrom being felt during perspiration and facilitating quick drying.Side-by-side type composite fiber filaments should preferably have amodification degree of 1.3 to 6.0. Such a modification degree of 1.3 to6.0 will serve to increase the number of gaps to be formed among singleyarns and increase the fiber density of the outer layer itself, leadingto a high water-permeability. The modification degree referred to hereinis defined as follows:

Modification degree=d1/d2,

where d1: the diameter of the circumscribed circle a of the fiber'scross section, and d2: the diameter of the inscribed circle β of thefiber's cross section.

The multifilament yarns (a) comprising side-by-side type composite fiberfilaments should preferably account for 30 wt % or more of the yarnsconstituting the outer layer or the middle layer of the knitted fabric.If the percentage is less than 30 wt %, it will be difficult for sweatto be absorbed through the knitted fabric's inner layer and transportedrapidly into the outer layer as described above and in addition, it willalso be difficult to achieve good characteristics in terms of theaverage of the stretch percentages and the average of the stretchrecovery percentages in the longitudinal and transverse directions. Thepreferred fabric forms to mix the multifilament yarns (a) into a fabricinclude conventional knitted union fabric with other type yarns, mixedtwisted fabric, paralleled yarn fabric, covering, and combined filamentyarn fabric, and an appropriate one may be selected depending on thepurpose of the product, knitted fabric production method used andknitted texture.

For the water-permeability stretch knitted fabric, the average of thestretch percentages in the longitudinal and transverse directions(average stretch percentage) should preferably be 55% or more, and theaverage of the stretch recovery percentages in the longitudinal andtransverse directions (average stretch recovery percentage) shouldpreferably be 60% or more.

The average stretch percentage and the average stretch recoverypercentage can be determined by the methods described in Examples. Thestretch percentage represents the degree of stretching of the knittedfabric, and as this value increases, clothes produced from the fabricwill follow the movements of the body more closely when worn and theknitted fabric will follow the quick movements during exercise moresmoothly, allowing the wearer to move easily without getting much tired.The stretch recovery percentage, on the other hand, represents thedegree of quick recovery of the knitted fabric stretched by themovements of the body to the original state, and as this valueincreases, clothes produced from the fabric will fit the body morecomfortably when worn and allow the wearer to move more easily.

The stretch percentage and the stretch recovery percentage should beused in the form of the average of the values in the longitudinal andtransverse directions of the knitted fabric. When worn in the form ofsportswear by a wearer who actually moves, the knitted fabric will bestretched in both the longitudinal and transverse directions, ratherthan in only one of them, because the knitted fabric is stretchedthree-dimensionally to suite the curved body of the wearer. Such threedimensional stretching characteristics are in good correlation andagreement with the average stretch percentage and the average stretchrecovery percentage, which represent the averages of the stretchpercentages in the longitudinal and transverse direction.

From the knitted fabrics, the average of the stretch percentages in thelongitudinal and transverse directions should be 55% or more, preferably70% or more, and more preferably 80% or more. An average stretchpercentage of less than 55% is not preferred because the knitted fabricwill not follow the movements when worn and used for hard exercise andwill make the wearer tired easily.

For the knitted fabrics, the average of the stretch recovery percentagesin the longitudinal and transverse directions should be 60% or more,preferably 70% or more, and more preferably 80% or more. If the averagestretch recovery percentage is less than 60%, the knitted fabric willnot recover the original shape after being stretched during exercise andwill not fit the body comfortably in following the movements of thebody. The appearance of the cloth will also be poor.

For the water-permeability stretch knitted fabric of the invention,there are no additional specific limitations on the structure etc. if itcomprises a multi-layered structure knitted fabric composed of at leasttwo layers, i.e., the outer layer and the inner layer. For instance, itmay have a multi-layered structure in which the outer layer is composedof at least two layers. In such a case, the structure may be such thatthe multifilament yarns (a) exist only in the middle layer and accountfor 30 wt % or more of it. Thus, the effect is achieved if themultifilament yarns (a) are contained in all layers or in one or morelayers that constitute the multi-layered outer layer.

The appropriate knitted fabrics include circular knitted fabrics such assingle jersey and double jersey; warp knitted fabrics such as singletricot, double tricot, single raschel, and double raschel, weft knittedfabrics such as single bed knit and double bed knit, and other knittedfabrics such as tights and hosiery.

There are no specific limitations on the yarns other than themultifilament yarns (a) to be used for these water-permeability stretchknitted fabrics. To produce products for sportswear, for instance,synthetic fiber multifilament yarns (b) may be used preferably tomitigate the stickiness during heavy perspiration.

To produce products for inner wear, synthetic fiber multifilament yarns(b), natural fiber, and semisynthetic fiber that are particularly highin hygroscopicity may be used particularly to mitigate the sweatiness.

There are no specific limitations on these synthetic fiber filamentyarns (b), and yarns conventionally used for clothing and othermaterials, such as those based on polyester, polyamide,polyacrylonitrile, polypropylene, polyvinyl alcohol, or polyvinylchloride, may be used. For further mitigation of stickiness on the skin,hydrophobic synthetic fiber filament yarns are preferred to hygroscopicsynthetic fiber filament yarns.

For instance, the preferred polyester-based fibers include polyethyleneterephthalate, polybutylene terephthalate, and polytrimethyleneterephthalate fiber. The preferred polyarnidebased fibers include, butare not limited to, nylon 6 fiber and nylon 66 fiber, and the preferredacrylic fibers include polyacrylonitrile fiber. Other preferred onesinclude protein fibers such as milk protein fiber and soybean proteinfiber, as well as polylactic acid fiber.

These synthetic fiber multifilament yarns (b) may be drawn yarns,crimped yarns, or filament mixed yarns that are mixed with otherfilaments, but the preferred ones include crimped yarns and combinedfilament yarns based thereon. In particular, the preferred crimped yarnsinclude false-twisted ones.

The shape of the cross section of the filaments that constitute thesynthetic fiber multifilament yarns (b) may commonly circular,triangular, elliptical, or multilobar, or filaments having two or moreconcave grooves along the length direction may be arranged on the fibersurface. There are no specific limitations on the cross-sectional shape,and the cross section may have a shape schematically resembling a letteror symbol such as E, F, H, I, K, M, N, S, T, W, X, Y, Z, and +. However,to achieve an increase in water-permeability, it is preferable for theouter layer of the knitted fabric to contain synthetic fibermultifilament yarns (b) that comprise filaments having two or moreconcave portions in the fiber's length direction. There are no specificlimitations on the modification degree of the filaments, but themodification degree should preferably be 6.0 or less to avoid fractureand fibrillation of the fibers that could occur to cause deteriorationin the processability and quality. If synthetic fiber multifilamentyarns (b) that comprise filaments having two or more concave portions inthe fiber's length direction are used in the inner layer of the knittedfabric, on the other hand, the modification degree of the filaments usedshould preferably be lower than the modification degree of theside-by-side type composite fiber filaments in the outer layer of theknitted fabric in order to achieve a water absorption back-and-frontmoisture content ratio of two or more and a water absorptionback-and-front diffusion area ratio of two or more, which represent amajor feature. If synthetic fiber multifilament yarns (b) comprisingfilaments with a high modification degree are used in the inner layer ofthe knitted fabric, the absorbed moisture will unpreferably tend to stayin the inner layer of the knitted fabric, making it difficult to achievea water absorption back-and-front moisture content ratio of two or moreand a water absorption back-and-front diffusion area ratio of two ormore, which represent a major feature.

The monofilament fineness of the filaments that constitute the syntheticfiber multifilament yarns (b) should preferably be in the range of 1.1.to 5.5 decitex. If the monofilament fineness is less than 1.1 decitex,the pilling resistance and the snag resistance will tend to deteriorate.If the monofilament fineness is more than 5.5 decitex, the texture willunpreferably become less pleasant.

There are no specific limitations on the total fineness of the syntheticfiber multifilament yarns (b), but it should preferably be in the rangeof 33 to 330 decitex to cover from thin to thick knitted fabrics.

The inner layer of the water-permeability stretch knitted fabric shouldpreferably be uneven with many convex portions scattered, rather thanbeing flat. If clothes of such a fabric with an uneven inner layersurface are worn, only the convex portions will come in point contactwith the skin to mitigate stickiness during perspiration of liquidsweat, and in addition, the outer layer of the multi-layered structureknitted fabric of the invention will be higher in density while theinner layer will be lower in density to allow the liquid sweat to moveefficiency by capillarity from the inner layer to the outer layer of theknitted fabric, improving the water-permeability and permeability aswell as the diffusion and drying capabilities at the outer layer.

A wide range of uneven shapes including longitudinal stripes, transverseborders, grid, twill, herringbone, dots, and moss stitch may be used,and there are no specific limitations on them if they consist of concaveand convex portions with height differences between them. There are nospecific limitations on the methods to be used to form such concave andconvex portions with height differences, and the preferred methodsinclude the use of a specific knitted texture, the use of thin and thickyarns, and a combination of them.

With respect to the knitting conditions for the knitting process, theloop length and the runner length should preferably be longer comparedwith the typical knitting conditions for the common yarns to achieve alower knitting density. This allows the side-by-side type compositefiber filaments to form crimps effectively as they are transportedthrough the dyeing step, enabling the production of a knitted fabrichaving high stretchability, stretch recovery, softness, and fluffytexture.

The gray knitted fabric produced may be heat treated, scoured, or dyedby methods generally used for knitted fabrics. The side-by-side typecomposite fiber filaments should preferably be relaxed, degummed, andheat treated at temperatures of 80° C. or more to ensure more effectivedevelopment of potential crimps. As additional treatment to this dyeingprocess, appropriate steps including the following may be performed:water-repellent finish, soil-resistant finish, antibacterial finish,deodorant finish, deodorizing finish, flame resistant finish,perspiretion absorptive finish, hygroscopic finish, fungus proofingfinish, ultraviolet ray absorption finish, and weight reduction finish.Subsequently, post-processing steps including calendaring, embossing,washer, gigging, printing, and opal finishing may be carried outappropriately to meet the end-use requirements for characteristics.

In particular, sweat absorbent processing should preferably be performedbecause it serves to further improve the intended water-permeability.

By selecting appropriate materials, the water-permeability stretchknitted fabric can serve to produce a wide range of products. Suchproducts include, for instance, fabrics for clothing such as sportswear,underwear, homewear, uniforms, and outerwear, and those for other goodsincluding lining, shoe material, supporters, hosiery, and gloves.

The sportswear includes running shirts and trunks, athletic shirts andtrunks, golf shirts, tennis shirts, cycle shirts, outdoor shirts, poloshirts, T-shirts, baseball undershirts, training wear, and sweat shirtsand pants. The underwear includes general women's underwear such asslips, camisoles, petticoats, shorts, underpants, tights, T-shirts,round-neck shirts, U-neck shirts, body suits, and girdles; general men'sunderwear such as T-shirts, round-neck shirts, U-neck shirts, runningshirts, underpants, tights, briefs, and trunks; sports underwearincluding modifications of the former such as wear for athletics,outdoor sports, and skiing; and underwear for workmen for outdoor andindoor work. The homewear include loungewear, pajamas, negligees, andgowns. The outerwear includes women's wear, men's wear, children's wear,and workwear. The lining products include those for sportswear, women'swear, men's wear, children's wear, ceremonial clothes, student's wear,and workwear.

EXAMPLES

Hereinafter, our fabrics and methods are described more in detail byreference to examples, which, however, are not intended to limit thescope of this disclosure.

Evaluation Methods

In these examples, quality evaluation was carried out by the followingmethods.

Average Stretch Percentage

The stretch percentage test was carried out according to the grab methodfor constant rate extension specified in the JIS L 1018 “knitted fabrictest method.”

Specifically, three 10 cm×abut 15 cm test pieces were taken in each ofthe longitudinal and transverse directions. A constant rate extensiontype tensile tester equipped with an autographic recorder was used, andfor both upper and lower positions, a clamp of 2.54 cm×2.54 cm and aclamp of 2.54 cm×5.08 cm were used for the outer layer and the innerlayer, respectively, with an interval of 7.6 cm. For each run, a testpiece was fixed to the clamps after removing slackness and tension. Itwas extended at a tension speed 10 cm/min to reach a load of 17.7N (1.8kg), and then the interval between the clamps was measured. Immediatelyafter this, the clamps were moved in such a direction that the loadwould be removed, until the clamp interval returned to the originalvalue of 7.6 cm. The behaviors during the loading and unloading processwere recorded on an autographic recorder in the form of curves for theloading, extension and recovery periods (see FIG. 1). The stretchpercentage LA (%) was determined from the curves using the followingequation, and represented by the average for three test pieces:

Stretch percentage LA (%)=[(L1−L)/L]×100

-   -   L: clamp interval (mm)    -   L1: clamp interval (mm) at a load of 17.7N.

The stretch percentage of the knitted fabric was measured for thelongitudinal and transverse directions, and the two values were summedup, followed by dividing the sum by two to determine the average stretchpercentage.

Average Stretch Recovery Percentage

To determine the stretch recovery percentage LB (%), the loading,extension and recovery curves drawn on the autographic recorder wereanalyzed, and the residual strain L2 (mm) was determined from the pointwhere the recovery curve reached a load of zero. Then, the stretchrecovery percentage LB (%) was calculated from the following equation,and represented by the average for three test pieces:

Stretch percentage recovery percentage LB (%)=(L3/L1)×100

-   -   L3: (clamp interval <L1>−residual strain <L2>) at a load of        17.7N.

The stretch recovery percentage of the knitted fabric was measured forthe longitudinal and transverse directions, and the two values weresummed up, followed by dividing the sum by two to determine the averagestretch recovery percentage.

Water Absorption Back-and-Front Moisture Content Ratio

On a glass plate, 1.0 cc of distilled water was dropped, and a 10 cm×10cm test piece of the knitted fabric was put on it with the inner surfacedown so that the inner surface would come in contact with the distilledwater. The test piece of the knitted fabric was left to stand for 60seconds, and transferred onto another glass plate, which was thensandwiched between two pieces of filter paper cut into the same size andleft to stand for 60 seconds under a load of 5 g/m². Subsequently, theweight of water retained in the knitted fabric was determined from thedifference between the weight of the knitted fabric after absorbingwater and the original weight of the knitted fabric, and the waterretention percentages of the outer and inner surfaces of the knittedfabric were determined from the weight of water absorbed by the twopieces of filter paper in contact with the outer and inner surfaces.Measurements were made for three test pieces of the knitted fabric. Theratio of water retention percentage (water retention percentage of outerlayer/water retention percentage of inner layer) was calculated fromthese measurements.

The value of the ratio of water retention percentage represents thestate of the absorbed water. Thus, if the outer layer has a large waterretention percentage and a large rate of water retention percentage, itmeans that the distilled water is transported efficiently into the outerlayer, indicating that the knitted fabric is high in permeability andfeels less sticky when worn.

Water Absorption Back-and-Front Diffusion Area Ratio

On a glass plate, 0.1 cc of an ink solution prepared by diluting acommercial ink product twice was dropped, and a test piece of theknitted fabric was put on it with the inner surface down so that theinner surface would come in contact with the ink solution. It was leftto stand for 60 seconds to allow the ink solution to be absorbed, andthen transferred onto another glass plate, where it was left to standagain with the inner surface down for 3 minutes. The same test run wascarried out for three test pieces of the knitted fabric. The diffusionarea of the ink solution in the outer and inner surfaces of the knittedfabric test pieces thus obtained was measured, and the area ratio(diffusion area in outer layer/diffusion area in inner layer) wascalculated from the measurements.

The value of the diffusion area represents the state of the absorbed inksolution. Thus, if the outer layer has a large diffusion area and alarge area ratio, it means that the ink solution is transportedefficiently into the outer layer, indicating that the knitted fabric hashigh water absorption, permeation and diffusion capabilities.

The fact that the outer layer has a large diffusion area also indicatesthat the knitted fabric can come in contact with the air efficiently andtherefore dry quickly.

Both the water absorption back-and-front moisture content ratio and thewater absorption back-and-front diffusion area ratio should preferablybe two or more, but the two ratios do not necessarily have the samevalue. The value of the water absorption back-and-front moisture contentratio is a key factor in decreasing the stickiness on the skin. On theother hand, the value of the water absorption back-and-front diffusionarea ratio has a larger influence on whether the knitted fabric can dryquickly.

Evaluation of Wearing Comfortability of the Water-Permeability StretchKnitted Fabric

T-shirts that fit the body comfortably were produced from the knittedfabric, and five test subjects who wore the T-shirts jogged on atreadmill at 12 km/hour for 10 minutes in a room adjusted to 25° C. and65% RH. Subsequently, the easiness of movement and stickiness duringperspiration were determined based on their self-assessment informationand the T-shirts were classified into three groups:

-   -   Excellent: able to move very easily, not sticky at all    -   Good: able to move as easily as in a common product, not        significantly sticky    -   Inferior: not able to move easily, significantly sticky.

Overall Performance Evaluation

The total points were calculated according to the criterion shown inTable 1, and the overall performance was evaluated as follows:

-   -   15 points or more: excellent (good as water-permeability stretch        knitted fabric)    -   10 to 14 points: good (not satisfactory as water-permeability        stretch knitted fabric)    -   9 points or less: inferior (inferior as water-permeability        stretch knitted fabric).

Example 1

A homo PTT sample with an intrinsic viscosity (IV) of 1.40 and a meltviscosity at 275° C. of 750 poise and a homo PET sample with anintrinsic viscosity (IV) of 0.60 and a melt viscosity at 275° C. of 650poise were melted separately, and discharged together at a spinningtemperature of 275° C. and a composition ratio of 50:50 (by wt %)through a composite-shape 48-hole spinning orifice designed to produce ayarn with a daruma-type cross section as shown in FIG. 2(1), and takenup at a spinning velocity of 1400 m/min to produce a side-by-side typecomposite unstretched yarn. The yarn was stretched by a drawing machineconsisting of a hot roll and hot plate and then, without being taken up,directly relaxed and wound up to produce a 110-decitex multifilamentyarn consisting of 48 filaments that were not in the same coil phase.The resulting multifilament yarn had a cross section of a snowman-likeshape.

A 22G interlock circular knitting machine was sued to produce areversible knitted fabric (gray fabric) consisting of a flat outer layerof 100% multifilament yarns (snowman-like shape cross section) and ameshed inner layer of 100% polyester-filament textured yarns by using amultifilament yarn (110 decitex, 48 filaments) composed of theaforementioned PTT/PET side-by-side composite fiber filaments as thecomponent yarn E2 shown in the knitting diagram in FIG. 3 and using a84-decitex, 36-filament, polyester textured yarn (Tetron supplied byToray Industries, Inc.) as the component yarn E1.

This gray fabric was relaxed, scoured, dyed, and finished according to adyeing method commonly used for circular knitted polyester fabrics toproduce a knitted fabric with a metsuke (mass per unit area) of 179g/m². The resulting knitted fabric had high water-permeability andstretchability with a water absorption back-and-front moisture contentratio of 4.0, water absorption back-and-front diffusion area ratio of4.3, average stretch percentage for longitudinal and transversedirections' of 79%, and average stretch recovery percentage of 85%.Furthermore, the outer layer of the knitted fabric was free of crimps.

According to wearing comfortability evaluation, the knitted fabricenabled easy movements during exercise and eliminated stickiness duringperspiration, indicating that it was a water-permeability stretchknitted fabric with excellent quality as a whole. Results are shown inTable 1.

Example 2

Polymer samples similar to those used in Example 1 were dischargedtogether at a composition ratio of 50:50 (by wt %) through acomposite-shape 36-hole spinning orifice designed to produce a yarn withan X-type cross section as shown in FIG. 2(2), and then subjected to thesame steps as in Example 1 to produce a 84-decitex multifilament yarnconsisting of 36 filaments that were not in the same coil phase.

Except that this yarn was used as the component yarn E2 in the knittingdiagram shown in FIG. 3, the same procedure as in Example 1 was carriedout for knitting and dyeing to produce a knitted fabric with a metsuke(mass per unit area) of 162 g/m² consisting of a flat outer layer of100% multifilament yarns (X-shape cross section) composed of the PTT/PETside-by-side composite fiber filaments and a meshed inner layer of 100%polyester-filament textured yarns. The resulting knitted fabric had highwater-permeability and stretchability with a water absorptionback-and-front moisture content ratio of 5.4, water absorptionback-and-front diffusion area ratio of 9.5, average stretch percentagefor longitudinal and transverse directions of 72%, and average stretchrecovery percentage of 89%. Furthermore, the outer layer of the knittedfabric was free of crimps.

According to wearing comfortability evaluation, the knitted fabricenabled easy movements during exercise and eliminated stickiness duringperspiration, indicating that it was a water-permeability stretchknitted fabric with excellent quality as a whole. Results are shown inTable 1.

Example 3

A multifilament yarn (110 decitex, 48 filaments) composed of the PTT/PETside-by-side composite fiber filaments and a 84-decitex, 36-filament,polyester textured yarn (Tetron supplied by Toray Industries, Inc.),which were the same as those described in Example 1, were usedalternately as the component yarn E2 in the knitting diagram shown inFIG. 3 while the 84-decitex, 36-filament, polyester textured yarn(Tetron supplied by Toray Industries, Inc.) was used as the componentyarn E1 to produce a reversible knitted fabric (gray fabric) consistingof a flat outer layer of 52% multifilament yarns (snowman-like shapecross section) and a meshed inner layer of 100% polyester-filamenttextured yarns.

This gray fabric was relaxed, scoured, dyed, and finished according to adyeing method commonly used for circular knitted polyester fabrics toproduce a knitted fabric of 170 g/m². The resulting knitted fabric hadhigh water-permeability and stretchability with a water absorptionback-and-front moisture content ratio of 3.2, water absorptionback-and-front diffusion area ratio of 3.9, average stretch percentagefor longitudinal and transverse directions of 70%, and average stretchrecovery percentage of 91%. Furthermore, the outer layer of the knittedfabric was free of crimps.

According to wearing comfortability evaluation, the knitted fabricenabled easy movements during exercise and eliminated stickiness duringperspiration, indicating that it was a water-permeability stretchknitted fabric with excellent quality as a whole. Results are shown inTable 1.

Comparative Example 1

Polymer samples similar to those used in Example 1 were dischargedtogether at a composition ratio of 50:50 (by wt %) through acomposite-shape 36-hole spinning orifice designed to produce a yarn withan circular cross section as shown in FIG. 2(3), and then subjected tothe same steps as in Example 1 to produce a 84-decitex multifilamentyarn consisting of 36 filaments.

Except that this yarn was used as the component yarn E2 in the knittingdiagram shown in FIG. 3, the same procedure as in Example 1 was carriedout for knitting and dyeing to produce a knitted fabric with a metsuke(mass per unit area) of 165 g/m² consisting of a flat outer layer of100% multifilament yarns (circular cross section) composed of thePTT/PET side-by-side composite fiber filaments and a meshed inner layerof 100% polyester-filament textured yarns. With a water absorptionback-and-front moisture content ratio of 1.3, water absorptionback-and-front diffusion area ratio of 1.9, average stretch percentagefor longitudinal and trans-verse directions of 78%, and average stretchrecovery percentage of 87%, the resulting knitted fabric failed to havesatisfactory water-permeability though having high stretchability.According to wearing comfortability evaluation, the knitted fabricenabled easy movements during exercise, but had significant stickinessduring perspiration, indicating that it was not a water-permeabilitystretch knitted fabric with satisfactory quality as a whole. Results areshown in Table 1.

Comparative Example 2

Except that in a 28G interlock circular knitting machine, the samemultifilament yarns (circular cross section) of PTT/PET side-by-sidecomposite fiber filaments as described in Comparative Example 1 wereused for all yarn feeding ports in the knitting diagram shown in FIG. 4,the same procedure for dyeing as in Example 1 was carried out to producea knitted fabric with a metsuke (mass per unit area) of 195 g/m². With awater absorption back-and-front moisture content ratio of 0.8, waterabsorption back-and-front diffusion area ratio of 1.0, average stretchpercentage for longitudinal and transverse directions of 81%, andaverage stretch recovery percentage of 89%, the resulting knitted fabrichad only poor water-permeability though having high stretchability.According to wearing comfortability evaluation, the knitted fabricenabled easy movements during exercise, but had strong stickiness duringperspiration, indicating that it was not a water-permeability stretchknitted fabric with satisfactory quality as a whole. Results are shownin Table 1.

Comparative Example 3

A multifilament yarn (110 decitex, 48 filaments) composed of the PTT/PETside-by-side composite fiber filaments and a 84-decitex, 36-filament,polyester textured yarn (Tetron supplied by Toray Industries, Inc.),which were the same as those described in Example 1, were used in theratio 1:3 as the component yarn E2 in the knitting diagram shown in FIG.3 while the 84-decitex, 36-filament, polyester textured yarn (Tetronsupplied by Toray Industries, Inc.) was used as the component yarn E1 toproduce a reversible knitted fabric (gray fabric) consisting of a flatouter layer of 28% multifilament yarns (snowman-like shape crosssection) composed of PTT/PET side-by-side composite fiber filaments anda meshed inner layer of 100% polyester-filament textured yarns.

This gray fabric was relaxed, scoured, dyed, and finished according to adyeing method commonly used for circular knitted polyester fabrics toproduce a knitted fabric of 169 g/m². With a water absorptionback-and-front moisture content ratio of 1.8, water absorptionback-and-front diffusion area ratio of 2.1, average stretch percentagefor longitudinal and transverse directions of 53%, and average stretchrecovery percentage of 55%, the resulting knitted fabric had highwater-permeability, but with slightly poor stretchability. According towearing comfortability evaluation, the knitted fabric hindered smoothmovements during exercise, though being free of stickiness duringperspiration, indicating that it was not a water-permeability stretchknitted fabric with satisfactory quality as a whole. Results are shownin Table 1.

TABLE 1 back-and-front back-and-front average stretch wearingcomfortability test results moisture diffusion average stretch recoveryeasiness of points content ratio area ratio percentage (%) percentage(%) movement stickiness 3 4.0 or more 4.0 or more 75 or more 80 or moreexcellent excellent 2 2.0 or more 2.0 or more 55 or more 60 or more goodgood less than 4.0 less than 4.0 less than 75 less than 80 1 less than2.0 less than 2.0 less than 55 less than 60 inferior inferior

Table 1 shows the points allotted to each of the evaluation items usedfor the overall quality evaluation.

TABLE 2 back-and- back-and- average front front average stretch wearingcomfortability moisture diffusion stretch recovery test results Surfacecontent area percentage percentage easiness of overall structure Type ofyarn mix ratio ratio ratio (%) (%) movement stickiness evaluationExample 1 outer: flat 110T-48F 100 4.0 4.3 79 85 excellent excellentexcellent (PTT/PET: snowman- like shape) inner: mesh 84T-36F — (PETtextured yarn) Example 2 outer: flat 84T-36F 100 5.4 9.5 72 89 excellentexcellent excellent (PTT/PET: X-SHAPE) inner: mesh 84T-36F — (PETtextured yarn) Example 3 outer: flat 110T-48F 52 3.2 3.9 70 91 good goodgood (PTT/PET: snowman- like shape) (1 × 1) 84T-36F 48 (PET texturedyarn) inner: mesh 84T-36F — (PET textured yarn) Comparative outer: flat84T-36F 100 1.3 1.9 78 87 excellent inferior inferior Example 1(PTT/PET: circular) inner mesh 84T-36F — (PET textured yarn) Comparativeouter, inner: 84T-36F 100 0.8 1.0 81 89 excellent inferior inferiorExample 2 flat (PTT/PET: circular) Comparative outer flat 110T-48F 281.8 2.1 53 55 inferior good inferior Example 3 (PTT/PET: snowman- likeshape) (1 × 3) 84T-36F 72 (PET textured yarn) inner: mesh 84T-36F — (PETtextured yarn) T: decitex, F: number of filaments PTT/PET: side-by-sidetype composite yarn composed of polytrimethylene terephthalate andpolyester, PET: polyester

Table 2 shows features of the test pieces produced in Examples 1 to 3and Comparative Examples 1 to 3 and results of evaluation.

INDUSTRIAL APPLICABILITY

We provide water-permeability stretch knitted fabrics over a widethickness range from thin to thick that have sufficiently high sweatremoving performance and stretchability and serve to produce sportswear,innerwear, lining, and other materials used in various fields.

1-6. (canceled)
 7. A water-permeability stretch knitted fabric of amulti-layered structure, comprising at least an outer layer and an innerlayer, wherein 30 wt % or more of said outer layer is accounted for bymultifilament yarns (a) that comprise composite fiber filaments composedof two types of polyester polymer materials adhered to each other sideby side in a length direction of the fiber, the water-permeability ofthe knitted fabric being such that both the water absorptionback-and-front moisture content ratio and the water absorptionback-and-front diffusion area ratio between the outer layer and theinner layer are two or more, and the average for the stretch percentagesand that for the stretch recovery percentages in the longitudinal andtransverse directions of the knitted fabric being 55% or more and 60% ormore, respectively.
 8. The water-permeability stretch knitted fabric asclaimed in claim 7, wherein at least one of said two types of polyesterpolymer materials comprises polytrimethylene terephthalate.
 9. Thewater-permeability stretch knitted fabric as claimed in claim 7, whereina cross section of the composite fiber filament yarns composed of twotypes of polyester poly mer materials adhered side by side to each otherin the fiber's length direction has at least one concave portion with amodification degree of 1.3 to 6.0.
 10. The water-permeability stretchknitted fabric as claimed in claim 8, wherein a cross section of thecomposite fiber filament yarns composed of two types of polyesterpolymer materials adhered side by side to each other in the fiber'slength direction has at least one concave portion with a modificationdegree of 1.3 to 6.0.
 11. The water-permeability stretch knitted fabricas claimed in claim 9, wherein the cross section of said composite fiberfilaments has a snowman-like shape.
 12. The water-permeability stretchknitted fabric as claimed in claim 10, wherein the cross section of saidcomposite fiber filaments has a snowman-like shape.
 13. Thewater-permeability stretch knitted fabric as claimed in claim 7, whereinmonofilament fineness of said composite fiber filaments is 0.1 to 11decitex and total fineness for the multifilament yarns (a) is 22 to 330decitex.
 14. The water-permeability stretch knitted fabric as claimed inclaim 8, wherein monofilament fineness of said composite fiber filamentsis 0.1 to 11 decitex and total fineness for the multifilament yarns (a)is 22 to 330 decitex.
 15. The water-permeability stretch knitted fabricas claimed in claim 7, wherein said outer layer has a multi-layeredstructure composed of at least two layers.
 16. The water-permeabilitystretch knitted fabric as claimed in claim 8, wherein said outer layerhas a multi-layered structure composed of at least two layers.